Commutator lead supports



April 1, 1958 B. OTTEWELL 2,829,239

COMMUTATOR LEAD SUPPORTS Filed Dec. 22, 1955 [H van for; Barry Ozd'ewefl,

is Attbrny United States Patent COMMUTATOR LEAD SUPPORTS Barry Ottewell, Peterborough, Ontario, Canada, assignor to Canadian General Electric Company, Limited, Toronto, Ontario, Canada, a corporation of Canada Application December 22, 1955, Serial No. 554,812

Claims priority, application Canada December 28, 1954 4 Claims. (Cl. 310-234) My invention relates to dynamoelcctric machines provided with commutators and particularly to means for supporting the risers or leads connecting the commutator segments to the rotor windings in such machines.

In dynamoelectn'c machine rotors provided with commutators leads are normally soldered or brazed to the commutator segments and to the ends of the armature coils. When the length of these leads is great and their spacing small it has been found necessary to provide some kind of supporting and spacing device to prevent the deflection and vibration thereof. One known practice has been to provide the leads intermediate their length with lashings of twine or glass cord forming rings at one or more places. Another known practice has been to apply to the leads before assembly small insulated spacing buttons which are riveted thereto. Both of these methods have disadvantages in manufacture and in service.

The object of my invention is to provide an improved support means for commutator leads which is superior in quality, which may be quickly and cheaply produced and which may be easily applied to the leads after they are assembled.

In accordance with my invention, 1 provide strips of insulating board provided with slots on one edge in the manner of a comb and apply these strips individually to the leads intermediate their ends with the leads snugly received in the slots between the teeth. The strips are bent into arcuate form during their assembly on the leads and successive strips are applied with their ends overlapping, whereby a complete short cylinder of the insulating board material is built up with the teeth portions thereof preventing sidewise motion of the leads relative to one another.

An understanding of my invention will be had from the consideration of the following description taken together with the accompanying drawings in which:

Fig. 1 is a view looking at the commutator end of the machine, a small segment only being shown;

Fig. 2 is a view taken on the line AA of Fig. 1 looking in the direction of the arrows;

Fig. 3 is a view partly broken away of one of the strips from which my supporting structure is built up; and

Fig. 4 is a view of a plurality of assembled strips.

Referring to the drawings, there is provided a commutator for a rotor (not shown) comprising segments 1 and armature conductors having ends 2. The electrical connection between the individual bars 1 and the appropriate conductors 2 is eflected by conductor strips 3 which are soldered or brazed to the commutator seg ments 1 at one end and similarly united with the ends of the armature conductors 3 at the other end. As is common practice, I have shown each alternate lead 3 wrapped with insulation 4 throughout the greater part oi its length between the conductor bar and the armature conductors. As shown there are relatively long sections of the leads 3 between the commutator bars and the armature conductors which are unsupported and in which severe vibrations may be set up in operation. To support the leads against vibration I supply serrated bracing structures 5 at one or more points intermediate their ends, two such structures being shown in the embodiment illustrated. Each structure 5 comprises a plurality of segments 6 one of which is shown on a somewhat enlarged scale in Fig. 3. Each segment 6 is made from a flat strip of insulating material such as laminated or reinforced phenolic resin sheet. Each strip has slots 7 cut in one edge thereof to provide a comb-like structure, the slots being of a width to snugly receive or house the leads 3, and the teeth 8 of a width to fill the space between adjacent leads. When each alternate lead 3 is insulated, as shown in the form of my invention illustrated, alternate slots are cut of sufiicient width to accommodate the insulated lead. Material of the strip 6 indicated by dotted lines at 9 at the ends of the strip is cut away to leave end extensions 10.

To apply my supporting structure to the leads, a strip 6 is applied by inserting the teeth between the leads, the corners of the teeth 8 being cut away as indicated at 11 to facilitate their entry, and as the teeth are worked between the leads the strip is bent in an arc. A second strip 6 is then applied with its end overlapping the end of the first strip so that one or more leads are accommodated in slots in both strips. Further strips are then applied in succession in a similar manner until a complete ring in the form of a short cylinder is formed with the teeth on one edge thereof intervening between adjacent leads. To anchor the structure 5 to the leads against displacement, lashings or bindings of flexible glass cord or the like, indicated at 12 in Figs. 1 and 2 are applied around the leads 3 and the strips 6 at their overlapping ends 10. The structure may then be varnished and baked.

The sheet material employed is of sufiicient stiifness to form a sturdy structure when completed as described and for each tooth to positively space and support adjacent leads, but can be bent without injury to the fiat are required which bendability eases the threading of the teeth between the bars.

While I have illustrated and described particular embodiments of this invention, modifications will occur to those skilled in the art. I desire it to be understood therefore that my invention is not to be limited to the particular arrangement disclosed, and I intend in the appended claims to cover all modifications which do not depart from the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent in the United States is:

1. In a dynamoelectric machine rotor having a segmented commutator and armature conductors and leads interconnecting respective commutator segments with said conductors for forming the electrical circuit for said rotor, the improvement comprising means for supporting said leads against vibration, said means comprising a short cylinder of insulating sheet material having alternate slots and teeth formed in one edge, the short cylinder engaging the leads intermediate their ends with the teeth interposed between adjacent leads, and binding means individually securing each lead to said ring for maintaining said ring out of contact with other parts of said rotor, thereby precluding the transmission of vibratory forces to said leads from all sources other than through their connections to said armature conductors and commutator segments.

2. A dynamoelectric machine rotor as claimed in claim 1 in which said short cylinder comprises a plurality of toothed strips of insulating sheet material individually applied to the leads with the teeth thereof lying be- 1:? tween adjacent leads and with their ends placed in overlapping relationship.

3. A dynamoelectric machine rotor as claimed in claim 2 in which said short toothed strips of insulating sheet material are cut from flat strips and bent to arcuate form when being applied to the leads.

4. In a dynamoelectric machine rotor having a segmented commutator and armature conductors and leads interconnecting respective commutator segments with said conductors for forming the electrical circuit for said rotor, the improvement comprising a ring of insulating material concentrically spaced from said commutator and in contact with said leads, outwardly protruding members on said ring housing each of said leads for limiting deflection thereof, and a rope binding of initially flexible material individually anchoring each of said leads to said.

ring for reducing vibration encountered during operation of said rotor.

References Cited in the file of this patent UNITED STATES PATENTS 

